This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The ability to target therapeutic or diagnostic proteins to the nervous system is limited by the presence of the blood-brain/nerve barriers. In this project we are testing the hypothesis that modifications of an F(ab2)2 fragment of a monoclonal antibody (IgG4.1) against fibrillar human A[unreadable]42 can be used for the molecular imaging of amyloid plaques in Alzheimer's disease (AD) using high field strength magnetic resonance microimaging (MRMI) (9.4 T). The ability of this contrast agent to image plaques in vivo in AD transgenic mice may lead to early diagnosis of AD in humans and also provide a direct measure of the efficacy of anti-amyloid therapies currently being developed.